RESUMO
Herein, we report the preparation of 1,2,4-thiadiazinane 1,1-dioxides from reaction of ß-aminoethane sulfonamides with dichloromethane, dibromomethane and formaldehyde as methylene donors. The ß-aminoethane sulfonamides were obtained through sequential Michael addition of amines to α,ß-unsaturated ethenesulfonyl fluorides followed by further DBU mediated sulfur(vi) fluoride exchange (SuFEx) reaction with amines at the S-F bond.
RESUMO
Inhibition of mushroom tyrosinase was observed with synthetic dihydropyrano[3,2-b]chromenediones. Among them, DHPC04 displayed the most potent tyrosinase inhibitory activity with a Ki value of 4 µm, comparable to the reference standard inhibitor kojic acid. A kinetic study suggested that these synthetic heterocyclic compounds behave as competitive inhibitors for the L-DOPA binding site of the enzyme. Furthermore, molecular modeling provided important insight into the mechanism of binding interactions with the tyrosinase copper active site.